Add a setting to activate workbench parts on mouse over

[warpdesign]

Now that we can split editors and terminals I think it would be a good idea to have the ability to activate editors/terminals on mouse over.

Of course this would be a new option that would be false by default.

[Tyriar]

cc @bpasero

[bpasero]

@warpdesign why would that be a good idea?

[warpdesign]

@bpasero Because it's faster/easier to switch between panels/split terminals this way using the trackpad. Also, when switching back to an editor by pointing and clicking to activate the editor, you end up with the cursor in another line you were before. By having auto-focus you end up where the cursor was before. If you just need to test a particular setting in your code, and switch back & forth between terminal and your editor just to modify this particular line and then run your command through the terminal it can be handy.

Another use case: if you are editing a file and want to navigate into the file tree using the keyboard, you need to activate it first. To do that you click inside the file browser, which will open the file the mouse is pointing at, or expand/collapse the folder the mouse is pointing at. You didn't want to do that, you just wanted to navigate into your files.

If you could simply point to focus, you would point your mouse over the filetree, then just use arrow keys to navigate inside your tree. Then just go back right where you were before by just moving your mouse over the editor again.

Terminal apps (like iTerm 2) offer such an option too: I guess they found it was a good idea too.